Accounting machine



y 1949 c. J. GOODALE ETAL ,1

ACCOUNTING MACHINE Filed March 22, 1945 4 Sheets-Sheet l Inventors 1 Charles J. Goodale, Harry B. Marvin,

b aM

Their Attps-ne g.

May 24, 1949. c GQODALE ETAL 2,471,150

ACCOUNTING MACHINE Filed March 22, 1945 4 Sheets-Sheet 2 lnventor's Charles J. Goodale, Harry B. Marvin,

Their Attorney.

May 24, 1949.

C. J. GOODALE ET AL ACCOUNTING MACHINE 4 Sheets-Sheet 5 Filed March 22, 1945 Fig.6.

E Inventors;

Charles J. Goodale,

Harry B. Marvin 7V PH Th e iZ AtboT-nqg May 2 1949- c. J. GOODALE EI'AL ACCOUNTING MACHINE 4 Sheets-=Sheet 4 Filed March 22, 1945 s r 52 m t as 14% r i av Km T b Patented May 24, 1949 AQCOUNTIN G MACHINE Charles 1". Goodale and Harry B. Marvin, Schenectady, N. Y., assignors to General Electric Company, a corporation of New York Application March 532, 1945, Serial No. 584,148

21 Claims. (0]. 235-61) This invention relates to accounting machines, and more particularly to an electrically operated accounting machine, and it has for an object the provision of a simple, reliable, and improved ma chine of this character.

An object of the invention is to provide an improved accumulator mechanism for performing additions and subtractions.

A further object of the invention is to control the counting movements of the accumulator counting elements by means of electric valve apparatus.

A further object of the invention is to control the electric valve apparatus by means of timing circuits having time constants corresponding to the digit numerals from 1 to 9 inclusive in order to eifect movements of the counting elem nts of the accumulators corresponding to the digit numerals.

A further object is to provide adding and t trvcting apparatus of the above character including means for effecting carryovers, setting up negative totals, and for clearing the accumulator.

In carrying the invention into effect in one form thereof, an accumulator is provided with a constant speed driving means and with a stationary holding member. Each of the orders of the accumulator has a counting element which is normally held in engagement with the stationary member. The engagement of the counting element with the driving means and the reengagement of the counting element with the stationary member is controlled by suitable electric valve means constituting a part of each order. The counting movement of the counting elements is controlled by controlling the time which the counting element is in engagement with the constant speed driving means. This is accomplished by means of a plurality of timing circuits having time constants corresponding to the digit numerals.

For a better and more complete understanding of the invention, reference should now be had to the following specification and to the accompanying drawings of which Fig. 1 is an exterior view in perspective of a preferred form of a device embodying the invention; Fig. 2 is a View in perspective of a portion of the keyboard and mechanism associated with the amount keys for making item entries and for selecting the timing circuits corresponding to the digit numerals of the item entries recorded; Fig. 3 is a View in elevation partly in section of two counting elements, the

constant speed driving means, and the electromagnets for moving the counting element into engagement with the driving means or with the stationary element; Fig. 4 is a view in perspective of a detail of the counting mechanism; Figs. 5a and 5b are simple, diagrammatic sketches of the electrical and electronic apparatus of the accumulator; Fig. 6 is a chart of characteristic curves which serve to facilitate an understanding of the operation of one portion of the electronic apparatus; and Fig. 7 is a fragmentary view illustrating the amount key lockout mechanism.

Referring now to the drawings, an accounting machin accumulator mechanism is mounted in a casing I of suitable construction. Although any suitable means may be provided for making item entries, a plurality of rows 2, 3, 4, and 5 of amount keys are illustrated for the purpose of simplicity. Beginning at the right-hand side, the rows 2, 3, and 4 belong to the units, tens and hundreds orders, respectively. The row 5 at the lefthand side of the longitudinal break belongs to the N order. For example, if the machine is to have nine columns the N column 5 would be the ninth column or the column belonging to the hundred millions order.

The accumulator is provided with a plurality of counting elements, one counting element for each order. These elements are preferably constructed in the form of wheels or disks. Two of these disks 5 and i are illustrated in Fig. 3. Although only two such disks are illustrated, it is to be understood that there is one counting disk for each order. They are all identical and the disk '1? is described as typical. It is made of a suitable magnetic material, e. g.,a nickel iron alloy having approximately 60% iron and 40% nickel. The disk i is mounted for rotation with respect to the shaft 8 and to this end it is provided with a bearing sleeve 70. which is freely rotatable on and axially slidable along the shaft 8. This sleeve is made of a, suitable nonmagnetic material such as brass. The disk 1 is provided with a flange lb upon which the digit numerals 0 to 9 inclusive are successively imprinted in the forward or positive direction as illustrated on the flange of the disk 5. As shown in Fig. 1, the counting disks are so arranged that the numerals on the flanges are located beneath the windows 9, ID, H, and E2 in the casing.

For the purpose of effecting rotation of the counting disks during a counting operation and for holding them against rotation at other times, a plurality of suitable means [3, It, etc., one for each counting disk, are provided for normally holding the disk in engagement with a stationary member, and for effecting engagement of the .rstitute? interengaging elements.

with a constant speed driving member during a counting operation. These means are illustrated as electromagnetic means, and since they are all identical, the electromagnetic means It is described as typical. It comprises two spaced-apart electromagnets having operating coils Ma and [4b which are wound on spools [4c and Mid respectively. 'tThesesspoqls are; secured to frames Me and l ifbysuitable fastening means. "The frames Me and 14 in turn are secured to supporting uprights [4g and Mn which are suitably secured to the bottom plate I5 of the machine.

The frame M is provided with a suitable bearing [6 in which the shaft iiisjeurnalled-ior rotation. The coil 14a is provided with a core member i -lz which is secured to the shaft 8 for rotation therewith. The coil I4b isxpmvidedtwith a stationary ccre member 147' which is secured to the frame Md. This stationary core 'member is provided with a centrally disposed circular open- I ing through =which the sleeve "1a and shaft 8' proiect. iTherotatable-core Mtisprovidedwith a ring t? which is made of a suitable nonmagnetic -mater-ial such as-brass and is suitably secured to the core member :asby swag-ing. Similarly. the stationary core member l-4j-isprovided with a ring Iiiwhic-h is made of brassor other suitable nonmagnetic-material and issecured tothe-core by swagingor iother-means. An enlarged vieW- of the ring -=I8=is' illustratedin'Fig; 4. This ring is -providedwith' a=plurality of indentations 18a -...whic lr are pressed into the-'ring-by a suitable niorming die. nsshown; the-ring l8 has twenty .oiltheseindentations. HoWever, it-might have ,-.difierent ntunber of such indentations.

For example :it might have =-ten indentations.

The; disk 'inand the rotatable ar-i-ng H are each -providedsWi th-an equal numberofosimilar in- .dentations which: are ithe counterparts of indentations .l 8a. .The indentations of the disk. together with; "theindentations of whichever of; the. Brings. the l disk.- is in.- contact with cm- Theringsll and I8 and the disk I are so. 1 designed that when. the indentationsofi the 1 disk .engage.:those-' ..of;.: either. :ring: the-disk -is.. separatecl "from the .zscorrespondi g'.magnet core l lisor M7; by a small .airgap, e. g. .018 in. ..The;disk 7:,- isiillustrated in its; normal: position, in engagement: with .the sta- -ti0nary,ring:|8.' .Whenzthe-v coil i ih is-energized.

the counting disk I. is. attracted .and held in en- :gagement:withathcgstationary ring 13. Similarly,

-When.1the coil Maris. energized zthe counting disk I .115 attracted and-held. inengagement with the .re-tatinggzrin 'i IT. The shaft: 8;.,is..driven,at at 'ccnstantispeed by suitable constant speed driving means i1S1lCh'...-&S7:l hi 2 (single. phase self-startin =synchrcnous;mctor atothe drive shaft ofwhich theshaft- 8 is connectedgthroughsuitable reduction gearing ;(not?shown) LAsshQWn'; in the elec-- .trical; diagram of; Fig: b,.the -motor i9 is supplicdiii iom a suitable. source of alternating voltage which is preferably a commercial 6.0. cycle source. .It, 1S:IQDIIGSBIltGCLiIKTFig; 5b.,by the two supply alines. all).

The. motor 19 is. preferably a e-pole motor. and

.:the reduction:gearing-.preferablyhas a .ratio of 5:1. Thus the synchronous speed of the motor .is, 18.00..RL9P. and the speed -of..the shaft 8 is "360 R". P. This speed'is equal-to. 8,6 mechanical degrees-tor .each cycle nix-the:v alternating voltage .Of :thesource .20 or".6-zreyolutions-v per-second. aThus- $118.".COI'fll4i'WhiCh isyfixed; tov the shaft rotates .at.. a speeduof- 6. revolutions per second.

:Since the digitnumeralsz (l -9; are equally spaced were the-source and .arreversing switch 22 controls the direction of rotation of the motor, thereby providing for adding or subtracting operations.

"In the position of the switch which is illustrated in- Figbb the motor operates in the adding direction. When the subtract key (Fig. 1) is deupressed-,-the switch 22 is operated to the reverse position and't-he-motor rotates in the reverse or subtract direction.

gfforqthe purpose of controlling the energization of the operating coils of the electromagnets which effect the alternate engagement of the counting disk of each order with the driving motor and the stationary: ho ldingrmember .suit- ---able electric valve 'control meansnare provided.

The electric valve :control meanssforxtheunits, tens and-hundreds orders are. showniinFigsa 5a and 51) within the dottedrectangles23,':24,1.and

respectively. The electric .valve control means $01" the N is -shown.-within-..the rectangle Z6.

Since the electric valve control: means; forall ordersections are.substantiallyidenticaLthe .electric valve control means ior thetensorder is described as typical of all. In describing .thisxoontrol means for the tens order sectionitrmay-be assumed that. the disk l. of Fig: 3 is z'theacount- Ming element for the tens order. The energization of theoperating coils; :1 4a andiliboi. .the electromagnet i4 is controlled by electric; valves 27 and 28 respectively underwtheqpontrol iota plurality of timing circuits shown :within: the dotted rectangle 29.

Although the electricvalves: 2i and28may be of any suitable type. they vare-.preferably .thyratrons' These thyratrons areprovidedwith anodes 27a. and .2'8a,xcath0des 27b: and .281), control grids. 27c. and 128.0, andxshield'grids. 27d and 28d, respectively. A smallamount of.mercury vapor 'or an inertgassuch. as. argon is contained within .theenvelope. Theprese-nce.ofggas. or

- mercury vapor converts the. usual pureielectronic discharge intov any are stream. The :output..:circuits of these thyratrons, i. e.;.the.anode-cathode circuits; are connectedacross a source of direct voltage which is represented by. the positive. and

: the negative .busesfifl, and..3l. "The. operating coils Mia and Mb of the electromagnetsare connected in the output-circuits of electric valves .2! and'28 respectivelyiin:.series--with.rvoltage -ment with the stationary ring [8. Consequently, the valve Z'l-and the operating coll Ma. are referrred to-as the run valveand the .run operating coil respectively, and-the ;v.alve.12 8.v and the operating; coil- Mb are referred. to. the

standby valveand the standby..operatin coil, respectively.

A: characteristic of- .electric valves .such. asthe :gthyratrons fl'i -and g visrthat thewalve. may be renderedconducting only by simultaneously making the voltage of both-,the'control. grid and..the

shield; grid less negativeonmore positivethana predetermined critical value.

i In order to maintain the valve 21 normally nonconducting the control grid 210 is connected by means of a conductor 35 to a point of negative voltage 36a on a voltage divider comprising resistors 3t, 31, and 38 connected in series relationship with each other. The upper terminal of the voltage divider is connected to the negative bus 3!. A direct voltage is supplied to this voltage divider by means of a rectifier 39 with which the divider is connected in series across the alternating voltage source 25. The rectifier circuit is traced from the upper terminal of the source by conductor 49 to the negative bus 3|, divider resistors 3t, 3i, and 38, rectifier valve 39,to the opposite terminal of source 20. this connection, the voltage of point 364: of the divider is negative with respect to the negative bus 3! by the amount of the voltage drop across resistor 36. i

The conductor 35 which is connected to the negative point 36a of the divider and to which the control grid 210 is connected also serves as a common conductor for supplying a negative bias voltage to the control grids of the run valves 4|,

42 and 43 of the units, hundreds and N order respectively.

Another characteristic of thyratron valves is that once the valve has become conducting, the grid is powerless to terminate the current flow in the output circuit. This can only be done by means external to the valve itself, i. e., either by interruptin the output circuit or reducing the anode voltage to zero, or to a value which is negative with respect to the voltage of the cathode. In order that the counting disk 1 may be engaged with either the rotating ring I! during a counting operation or with the stationary ring 18 when the counting operation is terminated, it must not be subject to simultaneous opposite attracting forces. Consequently, when either valve 21 or 28 becomes conducting the other valve must be rendered nonconducting. In order to provide for this alternate conduction of the valves 21 and 28 a commutating capacitor 44 is connected between the anodes El a and 28a of the two valves. This capacitor operates in the following manner. Assume that the standby valve 28 is conducting and that the run valve 21 is nonconducting. At this instant the voltage of the anode 21a is the voltage of the positive terminal of the source 30. The voltage of the anode 28a is positive with respect to its cathode only by the amount of the drop across the valve 28 which is a relatively small amount. Further assume that the valve 21 is rendered conducting by simultaneously making the voltage of the grids 21c and 21d less negative than the critical firing value. The valve 21 becomes conducting and a large voltage drop is produced across the operating coil [4a and the solenoid it and the resistor 33 in the anode circuit. As a result, the voltage of the anode 21a is suddenly decreased from a high value almost to the voltage of the negative terminal 3| of the source. The voltage across the capacitor 44 can change only as rapidly as the capacitor discharges and charges and since the capacitor cannot discharge and charge instantaneously, the voltage of the anode 23a. is instantaneously decreased the same amount that the voltage of the anode 21a is de creased. Consequently thevoltage of anode 28a is instantaneously decreased by a large amount which is sumcient to make it negative with respect to the cathode, thereby extinguishing conduction of run valve 21. As the capacitor 44 charges, the voltage of the anode 28a of the standby valve As a result of.

increases to the voltage of the positive terminal of the source.

If the standby valve is fired by simultaneously making the voltages 28c and 28d less negative than the critical firing value, the capacitor 44 operates in the same manner as described in the foregoing to extinguish conduction in the run valve. Thus the commutating capacitor 44 constitutes a means for terminating conduction in either valve in response to initiation of conduction in the other valve.

For the purpose of maintaining the counting disk I in engagement with the rotating ring I! for intervals of time which will effect amounts of rotation of the disk which correspond to the digit numerals, it is necessary to maintain the run valve 21 conducting and the standby valve 28 nonconducting for such periods of time. This is accomplished by means of a plurality of timing circuits having time constants which correspond to the digit numerals for preventing reestablishment of conduction in the standby valve for intervals of time corresponding to the digit numerals. These timing circuits are formed by the selective connection of the capacitor 46 in series with resistors 29a to 292' inclusive within the dotted rectangle 29.

The capacitor 5.6 is connected between the anode 21a of the run valve and the control grid 280 of the standby valve. When the run valve becomes conducting the capacitor 46 operates to make the voltage of grid 280 very negative with respect to the voltage of the cathode. This operation is similar to the operation of the commutating valve 44 described in the foregoing.

This selective connection of the resistors 29a to 29i inclusive is accomplished by means of the plurality of amount keys which are comprised in the row 3 of Fig. 1. There are nine of these amount keys, one for each digit of 1 9. Operatively associated with these amount keys is a corresponding plurality of switching devices 29 1' to 291' inclusive. The switch 29 which is typical of all the switches associated with the amount keys is provided with a pair of stationary contacts and with a movable contact which is normally separated from the stationary contact. The movable contact is provided with a button 29', Fig. 7, which normally projects into a slot on a cam 29" which is secured to the stem of the associated amount key. When the one amount key is depressed, the cam moves the button into the switch casing to cause the movable contact member to bridge the stationary contact members, thereby to complete the connection of the resistor 29a in circuit with the capacitor 46. Each of the amount keys is provided with a similar cam which actuates the button of its associated switch.

The resistor 29a has an ohmic value such that when connected in circuit with the capacitor 46 the time constant of the circuit is of the order of /eo second. However, this resistance value is not critical. It may vary 20 per cent. Thus, if the run valve is rendered conducting and the timing circuit through switch 297 is simultaneously completed, the voltage of the control grid of the standby valve is maintained below the critical firing value for slightly less than /60 second. The voltage of the shield grid is maintained below the critical firing value for /60 second, since the voltage of both grids must be above the critical value to render the standby valve conducting. In other words, the control grid circuit must restore the grid voltage of the standby valve to 7 eftringwaluewithin the desired lttsecondrsothat the shield grid may fire the valve: after rexactly t/smsecond. Consequently; theucoun ting disk is r ma'intained in: engagement with the rotating ring .1 il I aim /60 second rand V is -rotateda thrugh.= 36 adegrees afoiea:countxofi 1. Jlihe resistors-associtatedtwith ."the iamount keyssihave resistances 'which when connected: :in 1 circuit with: capacitor flmresult time constants which. produce rota- 'tionz of lthei 'c'ounting disk andnnumerieal vcouiits as shown in the following table:

"E1181: foregoing i tablebis merely illustrative oi moneivset' 'ofe values which produces satisfactory results with given circuit constants.

The-constructional details of the m'ounting. and alnterlockingrof the amount keys of rows 3aa-re 'xillustrated in EigL'Z. These amount keys are slid-;

minely 'mounted I in a suppo'rting upright 63; which :tiswsuitably secured'nto' the" frame of the machine. -In Fig.-2 awportion 'ofL this upright 68 is. broken :away: to: -reveal the detailed construction of the I amount "keywhich is typical: of all. :This.

eamount key is b'iased to itsxuppermost position m -means of -a tensionrspring 49': which isaacononected':-between the. upright 48 and a pin which .aissecuredito the stem of the key.

vvithi the 'rod of. thelswitchi-which. is actuated by ithevnext higher. amount :key. Thus, when the' 2 am'ount': key is: depressed; their red: of: the switch fiilkfis forced" into: thesslotxaon the-stem of. the: I 11.5 amount key,- thereby tot-prevent thelatter :from b'eingidepressed. Simultaneously; the slot onthe stem of a the 2* amount key: is moved i below T the :rlevelof the rodof: switch 29l=with the result that zswitch 291 cannot-be. operated and the 3 amount they cannot be depressed.

r'For tlievpurpose-of initiating conductiomof the :run a valve Y 21 win "response to depression ofan vamount rkey; switching means comprising three switches 54; 5*5,-and-56 are provided as shown-in 5.15rFig. 2. Each oi these switchesis similar in con- -struction to the switch 297. The actuatingbutton moi-each switch isprovided with a rod-whichpasses entirely; through the: switch and projects beyond its casing on the opposite side. The 'switchest l -and 55:==are, provided with normally closedconxtacts amend 55a respectively and-the switch 56 is provided-with normally closed-contacts'fifiw and. normally open contacts 561) as iillustrated in Fig. 512; r Asrshown-imEigs-z the switches 5.4,- 55;and =z=fifiwaremounted-on the upright-wand" are arranged in a vertical bank with the projecting rod --'of:one. resting against the button-of the-switch -which:is-immediate1y beneath'it.

-'The rod 58- "is [provided witha 'cam- 590- which i depresses' the button: of the switch- -Me-when the 'mdfmoves to the left, thereby opening the nor- -.-ma1-ly: closed contacts Ma -55a, and fifiwandclosing the normally opencontacts 55b.

starting capacitor fi'l-is connected from the negative "conductor through :normally closed contacts 56avto an intermediate. point of posi :tive voltage -on a voltage divider which comprises resistors 58 and: 59 connecteddn: series across-the direct voltage source-3mm. JI-hecapacitorlti'l fisuitable interlockingmeansare-1:pr0vided: for itlomi vnormally chargedwith the full voltage between rpreventingasecond: amountkeyin rtheztens-iorder irom beingddepressed. :untih arr: 8&T1i8l"3d3p18588(1 iukey hasibeerr released: and returnedto its :upperemosthposition. JI-Ehese :interlockingmeansr-comi priseeai bar :58 wwhich iis :slidably mountedein-i a r t. g rooveiirr the upr ight-' i8;-a;. bellcra'nk: 5 lior each akeygrancupper. pin 52w and a' lowera pin i 521) ion the istemi: of-seach key,-i a laten -a and a: -pin 'SIIbA'ifor each-ilcey-mounted on the bari fi. fi the i b'ellcrank isgpivotallyw secured to. the. upright 38 aand its :hori-zontale arm is biiurc ated :to; :provide tatslotimwhich the :pin' 52bslides. Whenwan i-amountkey; eE- grzthe amount 2 key; :is depressed sthe m'esultingl downward :movementr of pin: 52b

.i-=rotat'es lthewbellcrank 5 I 1 intzar counterclockwise t t-direction. A-"ften antamount. of f=rotation nwhich tist sliffieienti to permit. the l pp 6r'L-pin 52 data descehdto a=pointbelow the level of the latch fila,

the upright arm of the bellcrank 5| engages the 55-pin iobrand movesthe rod 50 to thed-eft against toi the tension of a spYring BS. lnzmoving to theleft, :the rod? 50. m'ovesithe rlatch 56a beneath-the top t-pins #52111 of t the undepressed ikeys iin :the l tens i 'order. Additionalrzinterlocking xmeanSEare :pro-

: vided dorgipreventing two adjacent? keys. .inwthe fi same column from ibeing nsimul-taneously detpressed. These interlocking-means.are.i1lustrat- Pectin Fig. Tam-which: the switches: 2.3 v -2-9k;.and e291 of thetens rorder ares shown'vtogether with ttheys arefoperated respectively. rrASFShOW-llp: the eactuatingfi button of each "switclrisr mounted. on a rodswhiclyproj ectsentirely through the switch teasing. :similarlvwthefstemmteach-amount key 'iss rovlded with a squareislot-*which cooperates t the l tzsand3-.amount--keys: by means of whichfir'zo.

the :points 58a and 35a acrossl its. terminals. whenztthe starting switch is operatedtoopen contact fifiat and close o0ntact.56b,-the. positive terminal of the. capacitor 51- isconnected to the control grid-21c ot-the run valve and the voltage of the capacitor is: applied across. a resistor 6B which is connected between the grid: and the negaative potential resistor 35. -As.a result, the volt- ..age ofv the 1 control grid w 210 is raised aboveJthe =.io-.'oritica1'iiring value. The. resistance of resistor l. Bills. of the. order of a -megohm. Consequently, .Lthe rate'of discharge.of capacitor 5'l-is ver low :and thehigh positive voltage .is. main-t'aindon tithe controLg-rid forv a. period slightly in excess of /.60 second.

v.- Asstated in the. foregoing. conduction in. the valve 2? canonly be initiated by=.simultaneously .raisinguthe voltages vof both. gridsll'lc and- 21d above the critical firing value. iln order. that the counting. disk shall registerithe. correct. count it :isnec-essary that the run valvebe firedhonly in predeterminedpositions of-the rotating ring I? inwhich the teeth of-the diskcan meshaccuratewly -Withthe teethof-the ring, irrespective of the relative positions-of the teeth of the ring. and the countingdisk at. the instanttof mdepressingwan amcunt key. Itis also-necessary'that the standwby valve:- be fired at the correct instant. at I the endof the -timing-.-intervaI -to effect accurate meshing of the teeth-oft the counting disl with theteethof thewstationa-ryring 1B. To accomslplish= this, -means-are-=provided.- 'forra-i-sing the voltage'of the shield: grids 21d and 28d of the run -.andstandby valves above the *criticaL values in Wm-timed relation toathez alternating voltage wave of the source 20 from which the synchronous driving motor is supplied. For this purpose, an electric valve blocking oscillator is provided. This blocking oscillator is illustrated within the dotted rectangle 6| in Fig. 5b. This blocking oscillator comprises a high vacuum electric valve [52 having its anode cathode or output circuit connected across the alternating voltage source 28. The cathode is connected to the side of the source 20 to which the cathodes of the run and standby valves are connected through conductor 40. The primary winding 63a of a transformer 63 and two resistors 64 and 65 are included in the anode cathode circuit. A resistor 6-6 and a blocking capacitor 61 are connected across the secondary winding $317 of the transformer. The voltage supplied from the source 20 to the anode cathode circuit of the oscillator valve 52 is represented in Fig. 6 by the sinusoidal curve 68.

This oscillator 6| has anode current, grid voltage and anode voltage characteristics which are represented by the curves '69, Hi and H, respectively. The anode voltage is a steeply peaked periodic voltage whose maximums occur once during each positive half cycle of the alternating voltage impressed on the anode of the oscillator valve. This voltage is transmitted through a capacitor l2 and conductors 13 and 14 to the shield grids 21d and 28d of the run and stand-by valves 21 and 28. The grids are connected through a resistor T5 to a point 31a of negative voltage on the voltage divider 3B, 31, 38 and are thus negatively biased below the critical firing value as illustrated by the horizontal portions of the curve 16 in Fig. 6 which represents the voltage of the timing voltage wave. However, the increase in voltage which is transmitted through capacitor I2 abruptly increases the voltage of the shield grids 21d and 28d to the critical value.

The result is that the voltage of the grids 27d and 28d equals or exceeds the critica1 firing value during a brief interval in each positive half cycle of the alternating voltage of the source 20. These intervals are represented by the peak portions 16a of the curve 16 above the zero axis. They are of approximately .001 second duration and are separated by equal intervals of time of /60 second. Thus, the electric valves 27 and 28 can be fired only during these brief intervals which are accurately timed with respect to the positions of the indentations of the rotating ring H. The position of the rotating ring on the motor shaft is initially adjusted so that when the run valve is fired during one of these intervals the counting disk is attracted into accurate mesh with the rotating ring. This accurate meshing results irrespective of the position of the rotating ring at the instant of depressing an amount key.

The voltage divider 36, 31, 38 and rectifier 39 provide the control grid bias voltages for the run and standby valves of all order sections of the accumulator. Similarly, the blocking oscillator provides periodic triggering voltages of brief duration for the run and standby tubes of all order sections of the accumulator.

The operation to record an amount in any order will be understood from the following description. Let it be assumed that it is desired to record the count or 8 on the counting disk '1 of the tens order. It is also assumed that the disk is in. the home or zero position, i. e. the numeral appears in the window H] in Fig. l. The control rid 28a of the standby valve of the tens order section is connected through a resistor 11 to the positive conductor 36. The resistor H i has a resistance of the order of one megohm. Since the grid 28c is connected to the positive side of the source 30, the standby valve 28 will be fired by the first peak of the triggering voltage which is supplied from the oscillator 6| to the shield grid 28d following the closing of the line switch 18 to connect the machine to the altermating voltage source 20. To record the count of 8, the 8 amount key in the tens order is depressed to close the switch contacts 29q, thereby to complete a timing circuit for the capacitor 46 through the timin resistor 29h. The depression of the amount key 8 moves the rod 50 (Fig. 2) to the left, thereby opening the normally closed contacts Ma, 55a and 56a and closing the normally open contacts 56b. As a result, the charge of the condenser 57 is applied to the control grid 2'50 of the run valve, and on the succeeding peak of the triggering voltage which is supplied from the oscillator 6| to the shield grid 21d the run valve 21 is fired. Responsive to the firing of the run valve, the commutating condenser 44 extinguishes conduction in the standby valve thereby deenergizing the standby operating coil Mb, and the timing capacitor 46 reduces the voltage on the control grid 280 of the standby valve below the vertical firing value. Simultaneously, the operating coil Ma is energized and attracts the counting disk 1 into engagement with the rotating ring 17. The disk is rotated in a positive direction. The commutatin capacitor 44 recharges rapidly after the beginning of conduction in the run valve. However, the voltage of the control grid 280 of the standby valve remains below the critical firing value for a period of time determined by the time constant of the timing circult comprising the capacitor 46 and the resistors 2971. and TI. As set forth in the foregoing table, this period is /60 second. Slightly prior to the expiration of this time interval, the voltage of the control grid 28c reaches the critical firing value. Exactly /60 second following the initiation of the run valve a peak of triggering voltage is supplied from the oscillator 61 to the shield grid 28d. Consequently, the voltages of both grids 28c and 28d are simultaneously above the critical firing Value and the standby valve 28 is fired. In response to the initiation of conduction in the standby valve, the commutating capacitor 44 extinguishes conduction in the run valve, thereby deenergizing the operating coil Ma. The conduction in the standby valve energizes the operating coil Mb, thereby attracting the counting disk 1 into engagement with the stationary ring Hi to terminate its rotation. In the period of 0 second during which the counting disk was in engagement with the rotating disk it was rotated through an angle of 288 degrees. As a result, the digit numeral 8 appears in the window l0.

Whenever the run operating coil l'4a is energized, the solenoid 45 which is connected in series with the run operating coil is also energized. As illustrated in Fig. 2, the solenoid 45 is secured to the upright 48 and its plunger 45a is connected to the rod 59. The energization of the solenoid 55 attracts its plunger in a direction to move it to the left. Consequently, the contacts 29g of the timing circuit are maintaind closed until the standby valve is fired again and conduction in the run valve is extinguished at the end of the time interval required for the count corresponding to the depressed key. Thus, an accurate count is insured regardless of the length of time which the operator maintains the key depressed.

If it is desired to subtract an amount from the total of the previously registered amounts in the accumulator, the subtract key in Fig; 1 is first depressed, thereby to operate the reversing switch 5.2 to its lowermost position to provide for rotation of the synchronous driving motor l9 in the reverse or negative direction. If it is desired to subtract 8 from what has been previously recorded above in the accumulator, i. e., 80, the 8 amount key in the tens order is again depressed. As a result, the operation described in the foregoing is repeated with the exception that the disk is rotated in the opposite direction; As a result, the disk is brought to rest after the rotation of 288 degrees with the numeral appearing in the window l0.

In order to provide for enacting carryovers from one order to the next higher order, each order section is provided with a carryover switch which is actuated by the countin disk of the next lower order. Thus, the unit's, tens, and hundreds order sections are provided with carryover switches 19, 80 and M, respectively. Also, the N order section is provided with a carryover switch 82, the purpose of which is to provide for the fugitive one which enters into calculations in which negative balances are shown as 9s complements. I

The carryover switches '19, 80, etc. are identical with the switch 291i (Fig. 2). As shown in Fig. b, the carryover switch 80 for the tens order is provided with normauy closed contacts 80a and normally open contacts 802). As shown in Fig. 3, the carryover switches are mounted beneath the electromagnets which control the movements of the counting disks. The means for actuating the carryover switch 80 of the tens order is described as typical.- The upright ldh is provided with bosses" having aligned holes in which a push rod 83 is slidably mountedI The lower end of this push rod rests upon the actuating button 800 of the carryover switch. The bearing sleeve in is provided at its right-hand extremity with a small cam 10 which is arranged in such a position with respect to the digit nu- Inerals on the flange that it engages the top of the push rod 83 midway between the count of 9 and 0. That is, the cam engages the push rod and closes the contacts of the switch 80 when a point appears in the window is halfway between the 9 and 0 digit numerals.

Cooperating with the carryover keys are carryover capacitors 84, 85 86 and 81 for the units, tens, hundreds, and N order sections, respectively.

These capacitors are normally discharged. For example, the carryover capacitor 85 is normally connected across the one megohm resistor 88 of the hundreds order. The circuit is traced from the lower plate of the capacitor 85 through the normally closed contacts 89a of the clear switch, by conductor 9!), normally closed contacts 86a of the carryover switch. conductor 9|, normally closed contacts 89b of the clear switch, normally closed contacts 92b of the starting switch of the hundreds order, resistor 88 and then by conductor 35 to the upper plate of the capacitor 8'5.

The manner in which carryovers are eifected will be understood from considering the following problem in addition. It is assumed that the amount 287 is recorded on the counting disks, 1. e., the units counting disk reads '7, the tens counting disk reads 8, the hundreds counting disk reads 2 and the remaining counting disks up to and including the N disk read 0. To the previously recorded amount of 287 the amount 513 is now to be added. The reversing switch 22 is in the upper position to provide for rotation of the shaft 8 in the positive direction. In response to the depression of the 5 amount key in the hundreds order the counting disk is advanced degrees in the positive direction so that the digit numeral 7 appears in the window ii. The operation is identical with that described in the foregoing for recording a positive amount on a counting element. The depression of the i amount key in the tens column advances the counting disk 36 degrees in the positive direction so that the numeral 9 appears in the window it. Similarly, the depression of the amount key 3 in the unit column advances the units counting disk 108 degrees in the positive direction so that the 0 appears in the window 9. During the passage of the units counting disk from the 9 to the 0 position the units carryover switch 19 is actuated to the lower position to open the normally closed contacts lea and to close the normally open contacts 7% and immediately thereafter to permit the movable contact member to return to the uppermost position to open the normally open contact 7917 and to close the normally closed contact 79a. During the brief interval in which the contacts iii?) are closed, the lower plate of the capacitor t l is connected to the positive terminal 33] of the source. The capacitor is charged with the full voltage between the terminal 3!] and the negative voltage of the point 36a. When the normally closed contacts tea are reclosed as a result of the carryover cam passing out of engagement with the actuating rod of the switch It, the positively charged terminal of the capacitor 8' is connected to the control grid 210 of the run valve 27 of the tens order over a previously traced circuit. As a result, the run valve 21 is fired when the next succeeding peak of triggering voltage is supplied from the oscillator iii of the shield grid 21d of the run valve. In a manner identical with that described in the foregoing, conduction is extinguished in the standby valve 28' and the tens order counting disk 7 is attracted into engagement with the rotating ring H. The starting switch 54 is in its uppermost position since no amount key is now depressed. Consequently, the normally closed contacts 54a. bridge the contacts 297 so that the count of 1 timing resistor 23a is connected in circuit with the timing capacitor After an interval of time of /60 second, the voltage of the control grid 280 of the standby valve reaches the critical firing value and an impulse of triggering voltage from the oscillator 6! is simultaneously supplied to the shield grid 28d. This results in firing the standby valve and extinguishing conduction in the run valve, thereby to attract the counting disk into engagement with the stationary ring l8. During the /60 second interval in which the counting disk was in engagement with the rotating ring ll it advanced 36' degrees in the positive direction so that the numeral 0 now appears in the window H). In a similar manner, when the counting disk I of the tens order passes from the 9 to the 0 position, the cam 7c actuates the tens order carryover switch 88 with the result that the counting disk of the hundreds order is advanced 36 degrees so that the numeral 8 appears in the window ll. Thus, the correct sum 800 is registered on the counting disks.

To illustrate the operation of the carryovers during subtraction, assume that the amount 754 is registered on the counting elements and that the amount 589 is to be subtracted therefrom. The subtract key of Fig. l is depressed to operate the switch 22 to its lower position to provide reverse rotation of the motor [9 and the shaft 8. The operator depresses the 5 amount key in the hundreds order, the 8 amount key in the tens or der and the 9 amount key in the units order. In response to the depression of the 5 amount key in the hundreds order, the counting disk in the hundreds order is rotated 180 degrees in the reverse direction so that the digit numeral 2 appears in the window I I. In response to depression of the 8 amount key in the tens order the counting disk of the tens order is rotated 288 degrees in the reverse direction so that the numeral 7 appears in the window l9. As the counting disk 1 passes from the to the 9 position in the reverse direction of rotation, the cam 70 actuates the carryover switch 89, thereby effecting a carryover into the hundreds order which is similar to that described in the foregoing example of carryovers in addition with the exception that the carryover is in the reverse direction owing to the reverse direction of shaft 8. Consequently, the counting disk of the hundreds order is rotated another 36 degrees in the reverse direction. so that the digit numeral 1 appears in the hundreds order window H. The depression of the 9 amount key in the units order effects a rotation of the units order counting disk 6 of 324 degrees in the reverse direction so that the numeral 5 appears in the window 9. In passing from the 0 to the 9 position, the units carryover switch '19 is operated to efieot a carryover of 1 into the tens order. Owing to the reverse rotation of the shaft carryover is in the reverse direction. Thus, the tens order counting disk 1 is rotated another 36 degrees in the reverse direction so that the numeral 6 appears in the window 19. Thus, the amount 165 appears in the windows.

In order to illustrate the carryover from the N order to the units order to provide the fugitive one in calculations involving subtractions in which a negative balance results, it is assumed that the amount 150 is registered and that it is desired to subtract therefrom the larger amount 22%. The numeral 0 appears in the N order window i2 and in all windows between the N order and hundredths order. The operator depresses the 2 amount key in the hundreds order, the 2 amount key in the tens order and the 4 amount key in the units order. In response to depression I of the 2 amount key in the hundreds order, the counting disk is rotated '72 degrees in the reverse direction so that the digit numeral 9 appears in the window II. In passing from the 0 position to the 9 position, the carryover switch 8| of the hundreds order is actuated and this eifects a carryover of 1 in the next higher order which in this case is assumed to be the N order. As a result, the counting disk of the N order is rotated 36 degrees in the reverse direction from the 0 position so that the numeral 9 appears in the N order window l2. The counting element of the N order in passing from the 0 to the 9 position effects a carryover in the units order. When the carryover switch 82 of the N order is actuated by the cam of the counting disk, the lower terminal of the N order carryover capacitor 87 is connected to the positive terminal 39 of the source and the capacitor charged. The return of the switch 82 to its normal position following the passage of the cam connects the positive terminal of the capacitor to the control grid of the run tube 4| of the units order over the following circuit: Normally closed conductor 93a of the clear switch, normally closed contact 82a of the N order carryover switch 82, conductor 94, normally closed contacts 931) of the clear switch, conductor 95, normally closed contacts 96a of the units order starting switch 96, conductor 91 to the control grid of the run tube 4| of the units order. On the next succeeding peak of triggering voltage which is supplied from the oscillator 62 to the shield grid of the run valve, the run valve is fired and the unit counting disk is rotated 36 degrees in the reverse direction from the 0 position so that the numeral 9 appears in the units order window. As the units order disk passes from the 0 to the 9 position the units order carryover switch 19 is actuated to effect a carryover of 1 in the tens order. This results in rotating the tens order actuating disk I, 36 degrees in the reverse direction.

In response to the depression of the 2 amount key in the tens order, the counting disk 1 is rotated 72 degrees in the reverse direction so that the digit numeral 2 appears in the window. Finally, in response to the depression of the amount key 4 in the units order the counting disk is rotated another 144 degrees in the reverse direction so that the numeral 5 appears in the units order counting window. Thus, in the units window the digit numeral 5 appears. In the tens order the digit numeral 2 appears, and in the hundreds order window the digit numeral 9 appears. In the next higher order window and in all succeeding windows up to the N order window the digit numeral 9 appears. If the machine is a 9 column machine the amount 999,999,925 will appear in the windows. This amount is recognized by accounting machine operators as the true 9's complement of the negative amount 74 which is the difference between plus and 224 minus. If the correct negative total is desired at this point in the calculations, it is obtained by subtracting the amount 999,999,925 from the amount 999,999,999 which is the negative equivalent of zero. In performing this subtraction the answer 74 is obtained. However, if there are further addition item entries, the total is not taken at this point. By operating the switch 22 to connect the motor I9 to the source for rotation in the positive direction, further additions may be made and the correct positive amount will appear in the windows if the additions total more than '74. For example, assume that the 9s complement negative balance which appears in the windows is 9 in the N order, 9 in the hundreds order, 2 in the tens order, and 5 in the units order, and that it is desired to add the positive amount 224. The operator depresses the amount key 2 in the hundreds order, the amount key 2 in the tens order, and the amount key 4 in the units order. In response to the depression of the amount key 2 in the hundreds order, the counting disk in the hundreds order is advanced 72 degrees in the positive direction so that the numeral 1 appears in the hundreds order window. In passing from the 9 to 0 position the hundreds order carryover switch 8| is actuated to effect a carryover of 1 into the next higher order which in this case is assumed to be the N order. Consequently, the counting disk of the N order is advanced 36 degrees from the 9 position to the 0 position so that the numeral 0 appears in the N order window. The N order counting disk in passing from the 9 to the 0 position effects a carryover of 1 into the units order as a result of which the units order counting disk 6 is advanced 36 degrees in the positive direction so that the numeral 6 appears in the units order window. In response to the depression of the amount key- 2 in the tens order, the counting disk 1 of the tens order is advanced '72 degrees in the positive direction so that the numeral 4 appears in the window. Finally, in response to the depression of the amount key t in the units order, the units order counting disk 5 is advanced 144 degrees in the positive direction so that the numeral 0 appears in the units order counting window. As the units order counting disk passes from the 9 position to the 0 position, the units order-carryover switch 19 is actuated to effect a carryover of 1 into the tens order so that the counting disk for the tens order is advanced 36 degrees from the 4 position to the 5 position and the numeral 5 appears in the tens order window. Thus, the amount showing in the window is 150 which is obviously the correct answer since the last two described calculations involved a subtraction of 224 from the amount 150 and then an addition of 224 to the balance.

If it was not possible to prevent a carryover in any order while an amount key in that order isdepressed, an incorrect result would be obtained because the timing circuit for the amount key depressed and the timing circuit for the carryover count of 1 would be simultaneously connected in parallel. This would result in incorrect timing action of the circuits involved. This inadmissible result is prevented by arranging the circuits so that the lead from the carryovercapacitor of each order passes through a contact of the starting switch in the next higher order. Consequently, if an amount key in any order is depressed during either a positive or negative carryover from the next lower order, the starting switch of the order in which the amount key is depressed is opened to interrupt the connection between the carryover capacitor of the next lower order and the control grid of the run valve of the order in which the amount key is depressed. This circuit cannot be completed until the depressed amount key is released and the run switch returned to its closed position. For example, if an amount key in the tens order is depressed, the run switch 54 is operated to its open position and the contacts 55a are opened. Thus, the circuit between the units order carryover capacitor 8 3 and the grid 270 of the run tube of the tens-order is interrupted at the open switch contacts 55a.

In order to provide for clearing the accumulator, i. e. restoring the counting disks to their 0- position, a clear key 98 is provided together .with clear switches 99, 89, IE3 and 93 for the units, tens, hundreds and N order respectively. As shown in Fig. 2, the clear switches are mounted on the uprights in which the amount keys are supported. For example, the clear switch 89 for the tens order is mounted on the upright 48. The actuating buttons of the clear switches are actuated by cam surfaces which are secured to a rod llll which is mounted for transverse sliding movement with respect to the supporting uprights. For example, the actuatin button 890 of the clear switch S9 of the tens order is operated by means of the cam surface lllla and similarly the operating button of the units order clear switch 99 is operated by means of a cam surface iillb. The buttons of the run switches for the higher orders (not shown in Fig. 2) are operated by similar cam surfaces carried on the leftward extension of the rod IIJI. The .stem of the clear key 98 is provided with a pin 98a which normally rests in the slot in the bifurcated end of the horizontal arm of a bellcrank lever I02 which is pivotally mounted on a supporting upright its. The rod M32 is provided with a pin lu l in cooperative relationship with the vertical arm of the bellcrank lever )2. When the clear key 98 is depressed, the bellcrank lever I02 is rotated in a counterclockwise direction so that its vertical arm engages the pin I04 and moves the rod lfll to the left. The rod If in moving to the left depresses the actuating buttons of the clear switches.

The rod I0! is further provided with cam surfaces H15, 36, etc., one for each order. These cam surfaces effect movement of the rod 53 in the tens order and corresponding rods in the other orders which actuate the starting switches.

The manner in which the accumulator is cleared is explained by assuming that the total I50 has been recorded by the counting disks and the clear switch is depressed to clear the accumulator. In response to the depression of the clear key, the rod IBI is moved to the left. This leftward movement of the rod iii! operates the clear switches of each order but not the amount key switches. For example, in the tens order, the normally closed contacts 89a and 3% are opened and the norm-ally open contacts 89d are closed. Corresponding contacts in the clear switches 99, I00 and .93 of the units, hundreds and N orders are operated to corresponding positions. Simultaneously, the operating red at in the tens order and corresponding rods in the other orders are moved to the left by the cam surfaces carried on the rod ml, of which the cam surfaces and I06 for the units and tens orders, respectively, are illustrated. The rod 50 in moving to the left opens the normally closed contacts 54a, 55a and 56a and closes the normally open contacts 5% of the starting switch of the tens order. This results in firing the run valve 21 and attracting the counting disk 1 into engagement with the rotating ring i'i. Thus, the counting disk 1 is rotated in the positive direction toward its 0 position. The opening of the contacts 54a not only interrupts the connection between the timing capacitor E5 and the count of 1 timing resistor 23a but also looks out the amount keys, so that the timing circuit for controlling the valves comprises the capacitor 46 and the one megohm resistor ll only. The time constant of this circuit is approximately /60 second which is greatly in excess of the amount of time required for the countingdisk to make a complete revolution. When the counting disk 1 passes from the 9 to the 0 position, the carryover switch 863 of the tens order is operated to open its normall closed contacts 80a and close its normally open contacts 80b and subsequently to reclose its normally closed contacts 89a and open its normally open contacts 8%. Inthe close position of the contacts 8017, the control grid 280 of the standby valve is connected through the closed contacts 89d of the clear switch and the contacts 82%; of the carryover switch to the positive terminal as of the direct voltage source. At this point the timing circuit comprises the capacitor ts con- .nected in series with the resistors ll and lot in parallel. The time constant of this circuit is second which corresponds to 18 degrees revolution of the counting disk or a count of one half. At the instant of the actuation of the carryover switch, the counting disk is 18 degrees from the 0 position. Thus, as the counting disk reaches the 0 position the voltage of the control grid 28c reaches the critical firing value and simultaneously a pulse of triggering voltage is supplied from the oscillator 6| to the shield grid 28d, with the result that the standby tube is fired. This terminates conduction in the run valve and attracts the counting disk into engagement with the stationary ring at the position of the counting disk with the numeral 0 appearing in the window. The clearing operation for the remaining orders of the accumulator is identical with the operation just described and takes place simultaneously as it is simultaneously initiated in all orders of the accumulator in response to the depression of the clear key.

Although in accordance with the provisions of the patent statutes this invention is described as embodied in concrete form and the principle thereof has been explained together with the best mode in which it is now contemplated applying that principle, it will be understood that the elements shown and described are merely illustrative and that the invention is not limited. thereto since alterations and modifications will readily suggest themselves to persons skilled in the art without departing from the true spirit of this invention or from the scope of the annexed claims.

What we claim as new and desire to secure by Letters Patent of the United States, is:

1. In an accounting machine, a constant speed driving member, a stationary member, a counting element normally in engagement with said stationary member, means for controlling the alternate engagement of said counting element with said stationary member comprising electric valve means provided with a control grid, means for controlling said electric valve means comprising a plurality of resistance-reactance timing circuits connected to said grid having time constants corresponding to different digit numerals, means for selecting for timing operation a circuit corresponding to a predetermined digit numeral, and means for controlling said electric valve means to efiect the engagement of said counting element with said driving member and to initiate the timing action of the selected circuit to control said valve means to effect the reengagement of said counting element with said stationary member thereby to effect an amount of movement of said counting element corresponding to said predetermined digit numeral.

2. In an accounting machine accumulator, a constant speed driving means, a stationary mem- I her, a counting element, a first electric valve ior controlling the engagement of said counting element with said driving means, a second electric valve for controlling the engagement of said counting element with said stationary member, a plurality of timing circuits for controlling said valves to eifect the engagement of said counting element with said driving means for periods of time corresponding to the digit numerals thereby to efiect amounts of movement of said counting element corresponding to said digit numerals.

3. In an accounting machine accumulator, a rotatably mounted driving member, means for driving said member at constant speed, a stationary member mounted in spaced relationship with said driving member, a counting element of magnetic material rotatably mounted in the space between said members, a first electromagnet for attracting said counting element into engagement with said driving member, a second electromagnet for attracting said counting element into engagement with said stationary member, electric valve means for alternately supplying current to the windings of said magnets, a plurality of timing circuits for controlling said valve means to excite the winding of said first electromagnet for periods of time corresponding to the digit numerals thereby to effect amounts of rotation of said counting element corresponding to said digit numerals, and means for selectively initiating the timing action of said circuits.

4. In an accounting machine accumulator, a rotatably mounted driving member, means for driving said member at constant speed, a stationary member, a counting element of magnetic material, a first electromagnet for attracting said counting element into engagement with said driving member, a second electromagnet for attracting said element into engagement with said stationary member, a normally non-conducting first electric valve for supplying current to the winding of said first electromagnet, a normally conducting electric valve for supplying current to the winding of said second electromagnet, a plurality of timing circuits for controlling the conduction of said first valve and the non-conduction of said second valve for periods of time corresponding to the digit numerals, means for selecting a timing circuit corresponding to a predetermined digit numeral, and means for initiating the conduction of said first valve and interrupting the conduction of said second valve for attracting said counting element into engagement with said driving member, and for initiating the timing action of said selected circuit to reestablish the conduction of said second valve and interrupt the conduction of said first valve thereby to efiect an amount of movement of said wheel corresponding to said predetermined digit numeral.

5. In an accounting machine accumulator, a rotatably mounted driving member, means for driving said member at constant speed, a stationary member, a counting element of magnetic material, a first electromagnet for attracting said counting element into engagement with said driving member, a second electromagnet for attracting said element into engagement with said stationary member, a normally non-conducting first electric valve provided with anode, cathode and control grid for supplying current to the winding of said first electromagnet, a normally conducting second electric valve provided with anode, cathode and control grid for supplying current to the winding of said second electromagnet, a plurality of timing circuits connected to the grid of said second valve for controlling the conduction of said first valve and the non-conduction of said second valve for periods corresponding to the digit numerals, means for selecting a timing circuit corresponding to a predetermined digit numeral, and means for initiating conduction of said first valve and interrupting the conduction of said second valve to attract said element into engagement with said driving member and for initiating the timing action of said selected circuit to control said valves to attract said element into engagement with said stationary member thereby to effect an amount of movement of said element corresponding to said predetermined digit numeral.

6. In an accounting machine accumulator, a rotatably mounted driving member, a stationary member mounted in spaced relationship with said driving member, a counting element rotatably mounted in the space between said driving and stationary members, each of said members and said element having a plurality of relatively high and low portions constituting interengaging members, a source of alternating voltage, a synchronous motor supplied from said source for rotating said driVing member, electric valve means for controlling the alternate engagement of said counting element with said driving member and stationary member, a plurality of timing circuits for controlling said valve means to effect engagement of said counting element with said driving member for periods of time corresponding to the digit numerals, and means for controlling said valve means to effect engagement of said counting element with said driving member at a predetermined instant in the alternating voltage wave of said source.

'7. In an accounting machine, a rotatably mounted driving member, a stationary member mounted in spaced relationship with said driving member, a counting element of magnetic material rotatably mounted in the space between said driving and stationary members, each of said members and said Wheel being provided with a plurality of relatively high and low portions constituting interengaging members, a source of alternating voltage, a synchronous motor supplied from said source for rotating said driving member, a first electromagnet for attracting said counting element into engagement with said driving member, a second electromagnet for attracting said counting element into engagement with said stationary member, electric valve means for alternately supplying exciting current to the windings of said electromagnets, a plurality of timing circuits for controlling said valve means to excite the winding of said first electromagnet for periods of time corresponding to the digit numerals, and means for controlling said valve means to initiate the excitation of the winding of said first electromagnet at a predetermined instant in the alternating voltage wave of said source.

8. In an accounting machine accumulator, a constant speed driving means, a stationary member, a counting element of magnetic material, a first electromagnet for attracting said counting element into engagement with said driving means, a second electromagnet for attracting said element into engagement with said stationary member, a normally non-conducting first electric valve provided with anode, cathode and control grid for supplying current to the winding of said first, electromagnet, a normally conducting second electric valve provided with anode, cathode and control grid for supplying current to the winding of said second electromagnet, means for interrupting conduction of either of said valves in response to initiation of conduction of the other of said valves, a plurality of timing circuits connected to the grid of said second valve for controlling the conduction of said first valve and the non-conduction of said second valve for periods of time corresponding to the digit numerals, means for selecting a timing circuit corresponding to a predetermined digit numeral, means for initiating conduction of said first valve to attract said counting element into engagement with said driving member and for initiating timing action of said selected circuit to initiate conduction of said second valve thereby to effect an amount of rotation of said wheel corresponding to said predetermined digit numeral.

9. In an accounting machine accumulator, a

constant speed driving means, a stationary memher, a counting element of magnetic material, a first electromagnet for attracting said counting element into engagement with said driving means, a second electromagnet for attracting said element into engagement with said stationary member, a normally non-conducting first electric valve provided with anode, cathode and control grid for supplying current to the Winding of said first electromagnet, a normally conducting second electric valve provided with anode, cathode and control grid for supplying current to the winding of said second electromagnet, means for interrupting conduction of either of said valves in response to initiation of conduction of the other of said valves comprising a capacitor connected between said anodes, a plurality of resistance reactance timing circuits each having a time constant proportional to a different digit numeral connected to the grid of said second valve for controlling the conduction of said first valve and the non-conduction of said second valve for periods of time corresponding to said digit numerals, means for selecting a timing circult corresponding to a predetermined digit numeral, a normally charged capacitor and means for applying the charge of said capacitor to the grid of said first valve to initiate conduction to attract said counting element into engagement with said driving member and to initiate the timing action of said selected circuit to attract said counting element into engagement with said stationary member thereby to eflect an amount of rotation of said counting element corresponding to said predetermined digit numerals.

10. In an accounting machine, a driving member, a stationary member, a counting element, a source of alternating voltage, a synchronous motor supplied from said source for rotating said driving member at constant speed, means for controlling the alternate engagement of said coun ing element with said driving member and said stationary member comprising electric valve means provided with a pair of control grids, means normally biasing both said grids below the critical firing value, a plurality of timing circuits for controlling said valve means for periods of time corresponding to the digit numerals, means for selecting a timing circuit corresponding to a predetermined digit numeral, means for applying a voltage to one of said grids to prepare said valve means for conduction and an electric valve oscillator excited from said source for supplying periodic voltage impulses to the other of said grids to initiate conduction of said valve means and the timing action of said selected circuit at a predetermined instant in the alternating voltage wave of said source.

11. In an accounting machine, a substantially constant speed driving means, stationary holding means, a plurality of successive ordinal counting elements normally in engagement with said holding means, a plurality of separate electric valve means, one for each of said counting elements for controlling the alternate engagement of each of said elements with said holding means and said driving means, a plurality of resistance reactance timing circuits operatively associated with each of said Valve means for controlling the associated valve means to effect engagement of the associated counting element with said driving means for periods of time corresponding to the digit numerals thereby to effect amounts of movement of said counting element corresponding to the digit numerals, and means for controlling said 21 valve means to effect carry-overs from one order to the next.

12. In an accounting machine, a substantially constant speed driving means, a stationary holding means, a plurality of successive ordinal counting elements normally in engagement with said holding means, a plurality of separate electric valve means, one for each of said counting elements for controlling the alternate engagement of each of said elements with said holding means and said driving means, a plurality of resistance reactance timing circuits operatively associated with each of said valve means for controlling the associated valve means to effect engagement of the associated counting element with said driving means for periods of time corresponding to the digit numerals thereby to effect amounts of movement of said counting element corresponding to the digit numerals, and means for controlling said valve means to effect the engagement of said elements With said driving means and to initiate the timing action of the timing circuit associated with the count of 1 of each order for efiecting carry-overs from one order to the next.

13. In an accounting machine, a substantially constant speed driving means, a stationary holding means, a plurality of successive ordinal counting elements normally in engagement with said holding means, a plurality of separate electric valve means, one for each of said counting elements for controlling the alternate engagement of each of said elements with said holding means and said driving means, a plurality of resistance reactance timing circuits operatively associated with each of said valve mean-s for controlling the associated valve means to effect engagement of the associated counting element with said driving means for periods of time corresponding to the digit numerals thereby to effect amounts of movement of said counting element corresponding to the digit numerals, means actuated by each of said elements in a predetermined position thereof for effecting carry-overs from each order to the next, and electrically controlled means associated with the lowest order and controlled by the highest order in a predetermined position thereof to cause the ordinal counting element of the lowest order to advance one numerical position to provide for the fugitive one.

14. In an accounting machine, a constant speed driving means, a stationary holding means, a plurality of ordinal sections each comprising an ordinal counting element normally in engagement with said holding means, a first electromagnet for attracting said counting element into engagement with said driving means, a second electromagnet for attracting said element into engagement with said holding means, an electric valve means for alternately supplying current to the windings of said magnets, a plurality of timing circuits for said valve means for controlling said valve means to excite the winding of said first electromagnet for periods of time corresponding to the digit numerals, means for selecting timing circuits corresponding to predetermined digit numerals, means for controlling said valve means to initiate engagement of said counting element with said driving means and to initiate the timing action of said selected circuit to control said valve means to efiect reengagement of said element with said holding means thereby to eifect an amount of rotation of said element corresponding to said predetermined digit numerals, and means for controlling said valve means to effect carry-overs from one order to the next.

15. In an accounting machine, a constant speed driving means, a stationary holding means, a plurality of ordinal sections each comprising an ordinal counting element normally in engagement with said holding means, a first electromagnet for attracting said counting element into engagement with said driving means, a second electromagnet for attracting said element into engagement with said holding means, an electric valve means for alternately supplying current to the windings of said magnets, a plurality of timing circuits for said valve means for controlling said valve means to excite the Winding of said first electromagnet for periods of time corresponding to the digit numerals, means for selecting timing circuits corresponding to predetermined digit numerals, means for controlling said valve means to initiate engagement of said counting element with said driving means and to initiate the timing action of said selected circuit to control said. valve means to effect reengagement of said element with said holding means thereby to effect amounts of rotation of said element corresponding to said predetermined digit numerals, and means for controlling said valve means to effect the engagement of said counting element with said driving means and to initiate the timing action of the timing circuit associated with the count of 1 of each order for effecting carry-overs from one order to the next.

16. In an accounting machine, a constant speed driving means, a stationary holding means, a plurality of ordinal sections each comprising a counting element normally in engagement with said holding means, means for controlling the alternate engagement of said counting element with said driving means and said holding means comprising electric valve apparatus provided with a control grid, a plurality of resistance reactance timing circuits connected to said grid for controlling said valve means to efiect engagement of said counting element with said driving means for periods of time corresponding to the digit numerals, and means for effecting carry-overs from oneorder to the next comprising a capacitor for each of said sections, and means controlled by the next lower order for connecting said capacitor to said grid thereby to control said valve means to initiate engagement of said counting element with said driving means and to initiate the timing action of the timing circuit associated with the count of 1.

17. In an accounting machine, a constant speed driving means, a stationary holding means, a plurality of ordinal sections each comprising a counting element normally in engagement with said holding means, means for controlling the alternate engagement of said counting element with said driving means and said holding means comprising electric valve apparatus provided with a control grid, a plurality of timing circuits connected to said grid for controlling said valve means to effect engagement of said counting element with said driving means for periods of time corresponding to the digit numerals, and means for efiecting carry-overs from one order to the next comprising a capacitor for each of said sections, means actuated by the counting element of the next lower order in a predetermined position thereof for connecting said capacitor to said grid thereby to control said valve means to initiate engagement of said counter element with said driving means and to initiate the timing action of the circuit associated with the count of 1, and switching means interlocked with said 23' counting elements for interrupting said capacitor connections during a counting operation thereby to prevent carry-overs during counting operations.

18. In an accounting machine, a constant speed driving means, a stationary holding means, a plurality of ordinal sections each comprising a counting element normally in engagement with said holding means, electric valve means for controlling the alternate engagement of said counting element with said holding means and said driving means, and a plurality of resistance reactance timing circuits for controlling said valve means to eifect engagement of said counting element With said driving means for periods of time corresponding to the digit numerals thereby to effect amounts of movement of said counting element corresponding to said digit numerals, means for reversing the direction of rotation of said driving means to provide for subtracting operation, means for controlling said valve means for effecting carry-overs from one order to the next higher order, and means associated with the lowest order and controlled by the highest order to cause the counting element of the lowest order to advance one numerical position to provide for the fugitive one.

19. In an accounting machine, a constant speed driving means, a stationary holding means, a

plurality of ordinal sections each comprising a counting element normally in engagement with said holding means, means for controlling the alternate engagement of said counting element with said driving means and said holding means comprising electric valve apparatus provided with a control grid, a plurality of timing circuits connected to said grid for controlling said valve means to control the engagement of said counting element with said driving means for periods corresponding to the digit numerals, and means for effecting carry-overs from one order to the next comprising a separate capacitor for each of said sections, means for charging said capacitor, and means actuated by said counting element of each order for connecting the associated capacitor to the grid of the valve means of the next higher order thereby to control said valve means to initiate engagem nt of the associated counting element with said driving means and to initiate the timing action of the count of 1 timing circuit associated with said valve means.

20. In an accounting machine accumulator, a constant speed driving means, a stationary member, a plurality of ordinal sections each comprising a counting element, an electric valve means for controlling the alternate engagement of said counting element with said driving means and said stationary element, and a plurality of resistance reactance timing circuits for controlling said valve means to effect engagement of said counting element with said driving means for periods of time corresponding to the digit numerals thereby to effect amounts of movement of said counting element corresponding to said digit numerals, and means for reversing the direction of rotation of said driving means to provide for subtracting operation.

21. In an accounting machine accumulator, a constant speed driving means, a stationary memher, a plurality of ordinal sections each comprising a counting element, an electric valve means for controlling the alternate engagement of said counting element with said driving means and said stationary element, and a plurality of resistance reactance timing circuits for controlling said valve means to effect engagement of said counting element with said driving means for periods of time corresponding to the digit numerals thereby to effect amounts of movement of said counting element corresponding to said digit numerals, means for controlling said valve means to effect carry-overs from one order to the next, means for reversing the direction of rotation of said driving means to provide for subtracting operation, and means associated with the lowest order in the accumulator and controlled by the highest order in passing from the 9 to the 0 position to cause the lowest order to advance one numerical position to provide for the fugitive one.

CHARLES J. GOODAIE. HARRY B. MARVIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,600,319 Cox Sept. 21, 1926 1,875,437 Friden Sept. 6, 1932 2,056,690 Slye -i Oct. 6, 1936 2,061,745 W adell Nov. 24, 1936 2,172,061 Ford Sept. 5, 1939 2,195,267 Bush Mar. 26, 1940 2,312,342 Lang Mar, 2, 1943 2,340,114 Duis Jan. 25, 1944 2,369,430 Brand Feb. 13, 1945 2,404,739 Mumma July 23, 1946 2,405,664 Mumma Aug. 13, 1946 2,416,793 Compton Mar. 4, 1947 

